1. Field of Invention
The present invention relates to a solar cell material. More particularly, the present invention relates to a photosensitizer dye applicable in dye-sensitized solar cells.
2. Description of Related Art
Not only the supply of fossil fuels is expected to run out in an imminent future, the high consumption of fossil fuels poses an alarming threat to the environment and public health due to their poisonous emissions into the atmosphere. Accordingly, scientists are constantly in the search and the development of renewable and sustainable energy sources. Currently, the renewable energy sources include: solar energy, wind energy, hydraulic energy, tidal energy, geothermal energy, biomass energy, etc. Among the various types of energy sources, solar energy has been the most pursued due to its abundant supply. Further, the application of solar energy is not limited by physical environment or geomorphology, and solar energy can be directly converted to electricity with the appropriate equipments and apparatuses, which are known as solar cells (or photovoltaic).
Recently, Grätzel and O'Regan have proposed a new type of solar cell known as dye-sensitized solar cells (DSCs), which offer many advantageous prospects, such as, high photoelectric conversion efficiency, high transparency, the capability of displacing of different colors by the cell, and flexibility in which the cell is capable folding up or bending. Hence, the dye-sensitized solar cells are well received in the industry. Typically a dye-sensitized solar cell is constituted with four parts including an anode/cathode for providing a channel of current flow, a semiconductor material (such as, titanium dioxide TiO2 or zinc oxide ZnO) for accepting and transporting electrons, a dye layer attached onto the surface of the semiconductor material by a self-assembly manner, and an electrolyte for transporting holes. The materials used at each part and the interface between each part in the dye-sensitized solar cell play important roles on influencing the photoelectrical conversion efficiency of the cell. Most particularly, wherein the dye used in the photosensitizer layer is the most critical in influencing the efficiency of a dye-sensitized solar cell.
Accordingly, to identify a dye that has a high absorption coefficient for enhancing the photoelectrical conversion efficiency of a dye-sensitized solar cell has been enthusiastically pursued in the dye-sensitized solar cell industry.